Power actuator



ch 24, i931. c. s. SRAGG ET AL .1,797,853

POWER AGTUATQR Original Filed Dec. 22, 192:5 3 Sheets-Sheet l E s Wil/111111111111011 w m ATroRNEY March 24, 19311. C, s, BRAGG ET AL 1,797,853

' 4 POWER AQUATOR Original Filed Deo. 22, 1925 v 3 Sheets-Sheet 2 KM@ ATTORNEY AMarch 24, 1931. c. s. BRAGG ET AL POWER ACTUATOR Original Filed Deo. 2,2, .1923 3 Sheets-Sheet 3 NNN www N mmm M m QM. ww@

ATTORNEYS rames any; 2e, resi agarran erstes l einen CALEB S. BRAGG, OF PACM BEACE, FLORIDA., VGTOR W. KLIESRAEH, OF PRT lVIASHIIN'G'LON, NEW YORK; SSIG-NOBS TG BRAGG-KLESRATH CORPORATION, GF LNG ISLAND CTY, NEW YGBH, A CGRPORATIGN OIF NEW YORK l Y rou/'nn servation Application led Becember 22, 1923, vSerial No. 682,345. Renewed Enly 5, 192g.

Our invention consists in the novel features hereinafter described, reference being had to the accompanying drawings, which illustrate .one embodiment oi the same, selected by us tor purposes of illustration, and the said invention is fully disclosed in the following description and claims.

The object of our invention is to provide a power actuator for the operation of brakes,

A0 gear shifts, clutches, steering gear, or other devices ordinarily operated manually, by hand or foot, by means of which the actual operation of the device may be eiected by power under the most minute manual control as to extent and direction of movement and degree of applied pressure or force, the manual control operating in saine directions and to substantially the. same extent as in similar installations operating wholly under 2c manual operation, provision being also made of the power actuating mechanism.

for enabling the actuated device to be manu-' ally operated in the usual direction and to the desired extent under any and all c onditions in case of thejfailure for any reason In other words, our new mechanism supplements the usual manual operations by eecting the actual work by power actuated means so as to relieve'the operator of the labor and 3o fatigue consequent ,upon the actual exertion ot the necessary power to effect the desired movements of the actuated devices, while preserving the same delicacy of adjustmentand application of power which is obtained by manual operation, and in addition providing a practically fool-proof mechanism in which the manual operations canfassert themselves to actually apply the power 'in the desired direction and to the desired extent in case of the failure of the poweractuating mechanism. Our improved power actuator can therefore be readily inserted in and made part of connecting means interposed between any ordina-ry device or mechanism now or usually operated manually, and the manually operated devices foractuating the same without the necessity of teaching the operators new methods of operation, with consequent liability of ,accident should the der the control of valve mechanism by which thehigher and lower pressures'may be reversed. with respect to the piston and by whichthe cylinder can be cut' od from the sources of both tliehigher and lower pressures to liold the piston in any desired arrested or inter-jacent posit-ion, ln practice the apparatus'can be operated in connection with an;-r desired means or establishing diierential pressures, as for' example, means for producing a partial vacuum, suchA as a suction device with or without a vacuum tanlr may be used :for the lower pressure and air at atmospheric pressure may be relied upon for the higher pressureor a duid compressed above atmospheric pressure may be relied upon for the higher. pressure, or we may employ compressed motor fluid above atmospheric pressure for the higher pressure, and a partial vacuum produced by suction mechanism for' the lower pressure, and whether compressed lluid or suction or both are used storage or equalizing tanks may or may not be employed in accordance with the requirements of the installation.

@ur power actuator is exceptionally well adapted for usein connection with internal combustion engines which at all times during their operation present differential pressures, Thus there is a suction produced by the cylinders-in drawing in the charges of explosive mixture, between the cylinders and the throttle ,valve,which is at its maximum when the engine is throttled down, and decreases 1s the throttle' is opened. There is also high compression in the cylinders which is greatest when the throttle is wide open and decreases as the throttle is closed. vOur power actuatorcan therefore be readily operated by .the suction from the intake manifold, or by compressed gases from a cylinder of the engine, Vor by both as preferred.

selected three practical applications of' our invention for purposes of illustration one being its application to the operation of the plied. Therefore it is convenient to arrange for the operation of the power actuator .for this purpose, by using the suction of the engine on one side of the power piston and normal air pressure on the other. In theA case of a motor boat or other vessel, however,`

where the power actuator is employed to operate the steering mechanism (for throwing a clutch or gear 'shift mechanism) the situation is quite different as these operations might be and in many cases wou d be performed when the engine was operating at open or full throttle, as well as when throttled down and in such case there might not be sufiicient suction with the throttle 'wide open, for example, to insure the quick and certain operation of the actuator. A In Vsuch case, therefore, we prefer to tap one of the engine cylinders in a well known way kand take a portion of the burnt gases under pressure into a pressure tank to supply the higher pressure for one side of the piston using the suction from the intake manifold for the lower pressure which will insure the necessary power under all conditions. Thus, if the engine were merely idling and it was desirable to' operate the actuator to operate steering mechanism, clutch, gear shift, or other device, the pressure in the engine cylinder would not be at its maximum, but the suction at the manifold would be at its maxi` mum and would insure the correct operat1on, even if there was a reduction of pressure in the pressure tank. On the other hand,

if the engine was operating at full throttle and the suction was below the maximum the pressure would be accumulated in the presvsure tank so that the operationof the actuator would be insured under those conditions.`

In the accompanying drawings,

Fig. l represents a diagrammatic vie-w showing our improved actuator fixed in the connections betweentheservice brake lever andthe brakes ofan automobile, and also connected to the intake manifold -of' the engine,`for the purpose of providing the lower pressure, the power actuator being shown in elevation.

Figf2 is a section View of our power acshowingthe valve mechanism reversed with respect to the piston so as to effect the return movement of the piston by the same power which moved it forward.

Fig. 6 is a detail perspective view showing a portion of the piston and the valve mechanism in detached or separated relations, to illustrate graphically the component parte of the valve mechanism.

Fig. 7 is an enlargeddetail sectional view of the controlling valve mechanism for the piston.

Fig. 8 is a detail view of a slight modification showing how pressure pipe may be connected to air intake of Fig. l.

Fig. 9 is a diagrammatic View showing the installation of our improved power actuator for operating the steering mechanism of a power boat or other vessel.

Fig. l0 is a diagrammatic view showing the application of our power actuator for operating simultaneously the brakes of an automotive vehicle and a trailer vehicle propelled thereby.

Fig. l1 is an enlarged detail view 0f the means including a flexible pipe for connecting the vacuum tank on the trailer with the intake manifold of the engine of the automotive vehicle.

Fig. l2 is a detail view illustrating one form of means for effecting the connection between the brake lever of the automotive vehicle and the actuating part of the motor actuator carried on the trailer.

Referring to the drawings, l, represents the power cylinder of our power actuator, which is preferably formed with both ends open, the ends being closed by front and rear heads, respectively indicated at 2 3, Secured to the cylinder in the desired manner,`as by connecting bolts, 4, see Fig. l.

The forward head, 2, of the cylinder is provided with a guiding sleeve, 5, in which is fitted a bushing, 6, held in position by an annular guiding ring, 7, at the inner end of the sleeve, the outer end ofthe sleeve being provided with a stuffing box, indicated at 8,

through which extends a longitudinally mov-` able valve actuating rod, k9. Within the cylinder, I, isa double acting piston, indicated at 10, and provided preferably with annular gaskets, 11-11, extending in-opposite direc-l tions and'. engaging the limerV surface ofthe cylinderffwall. `The piston, l0, is'provided r menace stuiiing box, 15, with which 'the Vrear head, 3,

of the cylinder is provided. l prefer to provide an annular packing, 14a, located between the end of the bushing, 14, and a shoulder aty the junction between the piston and the eX-' tension, or piston rod, 12, as shown in the drawings to assist in Ina-king a tight joint and to cushion the return movement of the piston. 1G represents a longitudinally movable valve sleeve, iitting the internal bore of the extension, 12, extending through the cylinder from one end to the other and having its forward end connected to the valve actuating rod, 9. ln the present instance 1 have shown the valve sleeve, 16, connected to the stem, 9, by rivet, 17, which also passes through a valvecollar, 18, on the exterior of the sleeve, 16, having its exterior surface ground lto t the interior of the bushing, 6, and adapted to close a small port, indicated at 19, in said bushing which communicates with a passage, 20, leading to the source of lower pressure, as Yfor example, the intake manifold, 21, einen internal combustion engine, 22, to which it is shown connected in Fig. 1, by a pipe, 23. An annular valve seat, 18e, of leather or other suitable material .engages the end of the collar, 18, to further insure a tight joint. 1 prefer to insert in the pipeline, 23, a vacuum tank, 23a, and check valve, 23?), as shown in Fig. 1, and to connect the tank by a pipe, 230, of considerable diameter, with the passage, 20, of the power actuator in order that a partial vacuum may be maintained at all times in this tank, sowas to insure quick response of the actuator as soon as the valve mechanism has placed the cylinder in communication with kthe tank. mechanism and consequent suction' through the pipes, 23, to the manif-old will have the,

eiiect of varying the percentage of air in the explosive mixture, 1 prefer to locate in the pipe, 23, a regulating valve, 23d, which can be so adjusted, while the engine is running idle and fully throttled, and the power actuator is being operated, so as to provi-de the necessary suction without danger of stalling the engine. rEhe valve sleeve,.16, tits snugly in the central aperture of the guiding ring, 7, and is provided in rear of the valve, 18 and within the collar, 7, with an annular series of ports, 16a. Then the parts are in normal position, as shown in Fig. 2, for example, the poi't, 19, will be closed by the collar, 18, and the poi-ts.A 16a, will be' closed by the .guiding ring, 7. The valve, 1'6, is-provided with two annular series of openings, indicated at 24 and 25, respectively, located in different trans-l verse planes lengthwise of the sleeve and the interior of the sleeve is provided with a partition or plug, 26, between these two seriesoli openings, which may be referredto as the higher and lower pressure openings respec- As the operation of the brake Y tively, 24, being the lower pressure openings, and, 25, the higher pressure openings of the valve mechanism.. The sleeve, 16, is also pro-- vided on its exterior with a valve or colla-r, 27, rigidly secured thereto in rear of the high pressure openings, 25,`the said collar having its peripheral surface ground to fit a chamber, 28, in the interior of the piston, 10, and to engage a shoulder at the rear end of the chamber when in normal position, as shown in Fig. 2, for example. rllhe sleeve, 16, is also provided with a similar valve or collar, ,29, between the two series of apertures, 24 and 25, and adapted to ht within a bushing, 30, within the piston, 10, the bushing being provided at its rear end with a shoulder, 31, against which the collar, 2S), abuts when the parts are in normal position, as shown in Fig. 2. ln Fig. 6, the collar, 2S), is shown detached, as is also the bushing, 30, but the position on the sleeve. 16,occupied by the collar 29, is indicated in dotted lines. 1n rear of the bushing,

3 0, is an auxiliary valve seat, 32, which may consist in this instance of a washer of leather or other suitable material, which will thus be held between the rear end of the bushing 30, and a shoulder formed in the piston so as to be engaged by the sliding valve or collar, 27, when the sleeve, 16, is moved forwardly a suiiicient distance, which in this instance is 5- ot an inch. similar valve seat, 33, is provided tor the valve or colla-r, 29, which is located at the forward end of the bushing, 30, and the bushing, 30, and valve seats, 32 and 33,

secured to the forward side of the piston in are held in position by a clamping ring, 34, ico

any desired manner as by screws, as shown.

rlhe bushing, 30, is provided with a port, 35, communicating with the cylinder in'rear of the piston, by means of passages 36. vThe y rear head of the cylinder is provided with a passage, 37, in exact alignment with the passages, 36,- and closed by a screw, 38. By means of this screw access may be had to the passages, 36, for oiling the valve mechanism 11o when desired. The chamber, 28, is also pro: vided with a port, 39, communicating by a passage, 40, extending lthrough the pist/on,

with the cylinder on the forward side of the piston. The rear end of the hollow extension,

12, which is really the piston rod, is conveniently provided with a block, 41, having an attaching eye', 42, and the plug, 41, is also lprovided with a port or ports, 43, for the admissionY of atmospheric air when air is used for the high pressure and suction for the low pressure in actuating the piston. The forward end of the rod, 9, is provided with anV attaching eye, 44.

The mechanism just described may be in,-

sorted 'in fixed position in any connections between a manually operated, part, as a hand lever, foot pedal, for example, and the mechanism to be actuated thereby, as for example, brake mechanism, clutch mecha- 13e nism, steering mechanism, gear shift mechanism, etc. In Fig. 1 we have shown our improved actuator inserted in the connection between a foot lever, indicated at 50, and provided with the usual retracting spring, 5l, and the brake mechanism of an automobile, by way of example, the parts being indicated diagrammatically in Fig. 1, in which the rear wheel brake bands are indicated at, 52, the brake shoes, at 53, pivoted at 54, and operated by a cam or eccentric, 55', by means of an arm, 56, connected by a link, 57, to an arm, 58, on the rock shaft, .59, a, retracting spring, 60 being provided for the' rock shaft, 59, and retractiiig springs, 61, being provided for the brake segments or shoes, 53. This brake mechanism is of known construction and forms no part of our present invention. The cylinder of the actuator is supported in xed position with respect to the chassis of the automobile or other automotive vehicle,`

in any desired manner. The forward end of the valve rod, 9, of the actuator is connected by aA link, 62, or rod, with the brake lever, 50, and the piston rod or extension, 12, is connected by a link, 63 with an arm, 64, on the rock shaft 59. This represents a conventional assemoly where our improved actuator is interposedin the connections between the foot actuated brake lever and the y rock shaft for applying the brakes to the rear wheels of an automobile, but it is to be understood that our improved actuator can be used in any other type of brake mechanism or in the connections for actuating other mechanical devices` than brakes, such as those enumerated heretofore, and others.

Referring now to thefoperation of our improved power actuator, it will be noted that the rod, 9, and valvesleeve, 16, have a certain amount of lost motion with respect to the piston. In this instance this lost motion amounts to if@ of an inch, but we do not wish to be limited to this exact distance. In any event, it is the distance which the valve sleeve,-

16, must be moved forward from its normal munication with the suction mechanism is cut position before bringing the valve or collars, 29 and 27, into contact with the valve seats, 33 and 32 respectively. Referring now to Fig. 2, which represents the position of the parts Aof our improved power actuator when.- in normal position, and assuming that, as indicated in Fig. 1, the passage, 20, in the forward head is connected with the vacuum tank and intake manifold of the autothe 'valve mechanism, atmospheric air has free, access to the front side of the piston through the hollow piston rod, 12, the rear end of the sleeve, 16, the ports, 25, in the sleeve, 16, the port, 39, and passage, 40, in the piston.` In

` this position of the piston, all connection If,now,it is desired to apply the brake mechanism or otherwise operate the power actuator, the foot pedal, 50, is moved forward` in the direction of the arrow, Fig. 1, against its retracting spring, 51, thereby drawing forward the valve sleeve, 16. As the sleeve, 16,

moves forward, the ports, 24, are withdrawn from the piston and brought into communication 4with the portion of the cylinder foi'- ward of the piston, which is thus placed in communication withthe suction tank. multaneously the collar valves, 29 and 27, are moved forward within the bushing, 30, cutting off the rear portion of the cylinder from the passage, 40, and establishing communication between the Iatmospheric air or higher pressure inlet, 43, and the portion of the cylinder in rear of the piston through the ports, 25, the port 35, inthe bushing, 30, and the passages 36, in the piston. The effect of the suction mechanism produced in this instance by the suction of the engine itself, although it might be produced by other suction means, is to rapidly exhaust the air from the cylinder on the forward side of the piston, and as the opposite end ofthe cylinder is in communication with the atmosphere, the iston will instantly move forward. If no urtlier movement of the foot lever is made, the piston will simply move far enough to bring the piston over theaperture, 24, in the valve sleeve,.see Fig. 4, thus cutting off the commu- 7this position. It is to be noted that a certain amount of rarifaction has been produced in the cylinder forward of the piston5 followed by an immediate forward movement of the 4 piston under the pressure of atmospheric air,

until the piston is brought into a balanced condition, in which it will remain as the comof, and no atmospheric air can be admitted rto the forward side of the piston. If the foot" lever is further depressed so as to move the 'valve sleeve further forward and again bring the ports, 24, outside of the piston and into ,communica-tion with the cylinder, the rarefaction of the air on the forward side of the lpiston will be instantly resumed, as will the Iforward movement of the piston. As a matter of fact, the movement Vof the piston'follows vvso instantaneously the forward movement of the foot lever, that the foot lever may be moved forward any desired distance before arresting it, and the piston will follow the movement and stop practically instantaneously when the forward movement of the foot lever stops, as the additional movement o f the piston in stopping is only equal to the incassa width longitudinally of the sleeve, 16, of the valve ports, 24. There is therefore no backward surging of thepiston, and no relief of pressure exerted thereby, but Athe force or pressure exerted by the piston can be as delicately and accurately gauged by the feeling of the foot as though'the power were actually being applied by the foot itself, and will be maintained just as long as the position of the foot on the lever` is maintained stationary. At the saine time it is to be understood that the muscles of the foot do'notperform anything in the way-of exertion beyond overcoming the resistance of the retracting spring, which may be employed in connection with the foot lever, so thatv the muscles are relieved of all fatigue or strain while the delicacy of manipulation yof the actuated mechanism is preserved to the same extent as where the actuated part is directly moved by muscular exertion. f

When the` piston ,has been moved forwardly so as to. exert its maximum-pressure on the brake, the lfurther movement of the foot lever 'will bring the collar valves, 29 and 27, against their auxiliar valve seats, 33 and 32 res ctively, t ereby additionally sealing the valve mechanism, and as .this marks the limit of the lost motion provided between the actuating part, to wit, the foot lever, andthe actuated part, to wit, the piston rod, the further pressure of the foot on the pedal-will add the -roperators strength to the power exerted by the power actuator should this be or become necessary. y lt will be obvious-that this construction the extent to which the operators foot moves the pedal forward to enable the actuator to foot lever, 50, `is relieved, the lever movesv rearward under 'the action of its retracting.

springLthus moving the valve sleeve, 16, rcarwardi and this shifts the. valves, 29 and 27, into the positions indicated in Fig. soA

as to place the forward 4 portion ofthe Cylinder in communication with thefj/atmosphere through ports, 25, 39.1and 40, while the suction mechanism isplaced in communicationwiththe cylinder in rear of thel piston through orts,l 24, 35 and 36.` This causes of thebrake mechanism, and 'if the foot 'is continually relieved from the foot lever, the piston will return to normal posltion, -although this return movement can be a1'- rested at any moment by checking the return 'those sources and the respective ends of the cylinders to move the piston in one direction or the reverse direction, or to disconnect both ends of the cylinder from said sources to arrest the movement of the piston and hold it stationary in balanced condition. In Fig. 8 l have shown the hollow piston rod, indicated at 12a, provided with a connection, 70, Y

communicating with the interior of the hollow piston-rod. By connecting the connection, 70, lby exible piping, '71, for example, with any source of pressure Huid, as a cylinder of an internal combustion engine, the

. device will operate in exactly the same manner. In some instances where a pressure fluid is employed, the suction may be dispensed with if desired, by placing the passage, 20, in communication with the atmosphere.

' ln the construction ofour power actuator, it has been found most important to provide luid tight valve constructions, in order 'to prevent leakage on either side of the piston duringl the operation of the device.` It is to be noted that the suction port, 19, or lower pressure port, is entirely shut ed from the internal' valve mechanism when the parts are in normal position,see Fig. 2, by the ground valve or collar, 18, and seat, 18a, which closes the port, 19, and the ring, 7, which closes the ports, 16a, in th`e valve sleeve, 16, the only channel of connnunication` which is open being that through the hollow piston rod, 12,

the sleeve,16, ports 25, 39 and 40, connecting the source of higher pressure, in this case atmospheric air, with the cylinder forward of the piston. When the valve sleeve, 16, is moved forward into open position, as shown Y in Fig. 3, the ground valve collars, 29 and 27,

will be brought' into engagement with the auxiliary valve seats, 33 and'32, respectively, so that there can be no leakage of air into the portion of the cylinder forward of the piston where the suction is taking-placeto interfere with therapid attenuation of the air in that portion of the cylinder. This is secured both by the Vlit ofthe valve collars themselves in their enclosing parts, and "also by contact between the front'facesof saidycollar valves 'and theauxiliary seatsfofleather orother suitable materialiwhentlievalvemecha'- nism is ,in the interjacent positionshown in Fig. 4, thesuction can only act as far as the ports, 24, in the valve sleeve which are closed yv the Walls of the piston plate, 34, and the atmos heric air is cut off from the forward side o the-piston by the collar valve, 27, closingthe port, 39. v

It will be seen from the foregoing description that when our power actuator is insertedV and fixed in the connections between a manually operated lever or pedal and the part to be actuated, the pedal or lever lis operated in substantially the same direction and manner and to substantially the same extent that it would be if it was directly connected to the actuated device, theonly difference being that the actual ower transmitted to the actuated device is urnished by .the powerV cylinder, and the piston, under delicate control of vthe manually operated leveror pedal, and the1 manifold has become broken or injured so` that it leaks, as might occur by accident or otherwise, and the operator desires to apply the brakes, by moving the foot lever, 50, forward Until the parts are brought into the position indicated Iin Fig. 3, with the valve collars, 29 and 27, in Contact with the auxiliary seats, 33s and 32, there would be no suction to effect the forward movement of the piston, but in such case the operator, by simply pressing the pedal, 54, forward to a greater extent, can positively move the piston and piston rod, 12, to the/desired extent to apply the brakes with the desired force by the eX- ertion of the necessary muscular'strength and the only additional effort required would be the friction of the parts, which would be negligible. The forward movement of the piston would not be retarded by any compression within the cylinder as the valvemechanism being -in the position indicated in'Fig. 3, atmospheric air could iow into the cylinder in rear of the piston and be discharged freely from the cylinder in advance .of the "piston through the ports, 24, 16a, 19, and passage, 20. After applying the brakes, when the pedal is released, the retracting springs 51 and 60, would insure the rearward movement of the sleeve, 16, and as soon as the collar valves, 29 and 27, have reached therear end of their limited movement, permitted by the provision for lost motion between the sleeve `and piston, the spring, 60, would move back to its normal position, air being admitted through theport, 39, and passage, 40, to the forward side (of said piston, and air being expelled through lthe passage, 36, port, 35, and ports, 24C, and thence through the passage, 20, to the atmosphere. The apparatus herein described can therefore be inserted and fixed in the connections between any ordinary manually operated device and the part or parts to be actuated thereby without danger of accident which might otherwise result by a failure of the power actuated mechanism, as in the event of such failure the manual operation of the actuated part can be readily eifectedin'eXa-ctly the Asame manner that it would be if the power actuated device was not in the connections except for the slight ylost motion provided in the valve mechanism and the equally slight retardation due to the friction of the parts which would not in any way interfere with the proper operation of the actuated part.

Suitable means for lubricating the moving partsof thepower actuator can be provided by means of oil cups, oil saturated packings for the stuiiing boxes, and otherwise,

as is customary in ower'operated devices. In the drawing we iave shown an voil cup, 7 5, on the rear head of the cylinder, communicating by passage, 7 6, with the bushing vthrough which the hollow piston rod or stem, 12, slides, and by an aperture 1n the piston rod, indicated at I7, with the valve sleeve for lubricating these `parts. y

The interior of the valve mechanism can be oiled by removing the screw, 38, and inserting a longnecked oiler into the passage, 36. The cylinder, 1, is also preferably provided 'with an oil hole closed -by a screw, 1a, which can be removed to permit of lubricating the cylinder Walls and piston leathers, 11.

The vacuum storage tank, the regulating valve and the check valve, interposed in the connections between the reversing valve mechanism of the actuator, and the charge introducing suction passage of the engine between the` throttle valve and the cylinder,or cylinders, ordinarily the intake manifold, perform important functions 1n connection with our improved actuator. If the suction passage were directly connected to the actuator, the air withdrawn from the actuator, 1f withdrawn suiciently rapidly,to insure the prompt operation'of the actuator, would be carried into the suction y'passage so rapidly as to be likely to stall the engine if idling, by diluting too greatly the explosive charge as, when the throttle is closed (as it should be when the actuator is used to operate a brake),

the greatest possible rarefication will take place within the suction passage. When the throttle is wide open, there is little or no rare- Iication produced. If the connection was restricted so as to prevent the too rapiddelivery of the air withdrawn from the'actuator into the suction passage of the engine, it

averses or regulating valve which is interposed bemotor on the other.

tween the storage space or vacuum tank and the suction passage, restricts the passage of air withdrawn from the actuator cylinder into the suction passage or intake manifold, and this cooperates with the tank in insuring the operation of the actuator and preventing the stalling of the engine. lt will also be* seen' further, that as lthe degree of rarelicaf tion in the suction passage varies continu-` ously with the opening or closing of the throttle, the degree'of rarefication in the vac` uum tank, or storage space, Would be continually varying if it were not for the provision of the check valve. By the employ# ment of this check valve, the' maximum rarefication Within the vacuum tank or storage space, Will be 'obtained the first time the throttle valve of the engine is closed, as in changing gears, etc. The vacuum tank givesf the necessary capacity and the check valve maintains this maximum rarefication, so that both are instantaneously available Whenever it is desired to operate the actuator, as, for example, in ap lying the brake, thus obtaining accelerate and practically instantaneous acti-on of the actuator Without danger'of stalling the motor on the one hand, and Without the necessity of Waiting until the necessary quantity of air could be exhausted'bythe,

It is to be understood that it is 'particularly important in the opertion of our improved actuator not to stall the motor as thevacuum would be destroyed if the engine is not functioning.

lullig. 9 We have illustrated diagrammatically an installation showing our power actuator arranged to operate the steering mechanisrn ofla povver boat driven by an internal combustion engine, by Way of illustration.

- ln this figure, 80, represents` the hull of the boat, S1, the propeller, driven by an intelnal combustion engine, 8 2. 83 represents the rudder, Sli-,the tiller or arm' for operating the same Which'in'this installation would extend tuating' rod, 90, being connected by a link, 88, to the steering lever, 85, and the piston rod,

129, being connected by a link, 8 9, to'thef'tiller or steering arm, 84. lt will be understood that when the rudder is in neutral position, or in other Words in line with the longitudinal axis of the boat, the piston of the actuator Will be located substantially centrally in the cylinder'. The cylinder is supported in fixed position in the hull by any suitable means.

91 represents the vacuum tank connected by pipe, 92, with the suction passage in the for-v Ward end of the cylinder, said tank being connected by a pipe, 93, with the manifold, 94,.

of the internal combustion engine, 82, and

provided, as before stated, with a regulating valve, 95, and a check' valve, V96. The vacuum tank, regulating valve and check valve perform, in this connection, the same functions as above described, and these functions are even more important in a construction Where the higher pressure is obtained by burnt gases taken from a cylinder of the engine, as the introduction of too great a quantity of auch burnt gases into the suction space, or manifold of the engine, would be more apt to stall the motor than the same quantities of air. In this instance'we also .employ a pressure tank, indicated at 97, connected by a pipe` 98, with a cylinder of the internal combustion engine, and provided Awith a pressure tank, 97, and the pressure tank is connected by a flexible pipe, 100, with the interior ofthe hollow piston rod, 120. rIn operating our power actuator under these conditions, the forward movement of the hand lever or steering lever, 85, Will move the valve sleeve for- Ward vand connect the cylinder forward of the piston with the vacuum tank, 91, and the portion of the cylinder in rear of the piston With the pressure tank', 97, thus creating dif- -fere'ntial pressures which will' cause the piston to instantly move forward as the lever, 85, is advanced, and if the lever, 85, is held stationary the piston will immediately be brought to a balanced condition as hereinbefore described. The rearward movement of the lever, 85, will likewise efect the return Amoa/ement of, the vpiston in -the manner previously described. ln this installation it willrbe seen that the difference tof pressures necessary to secure the instantaneous operation ofthe actuator will always be present' under all conditions.. lf the engine is running very slowly, with the throttle nearly closed, the pressure in the engine cylinder will be less, but the suction at the manifold .between the throttle valve and the cylinders of the engine. will be greater when the throttle vis open w1( er.

will beV less suction at the manifold but the pressure in the .Cylinders willbe greater and lf the enginevis runningwith the throttle Well opened, or fully opened, there the throttle valve of the engine, there will always be suflicient differences of pressures to secure the operation of the device, for as the p suction decreases the pressure increases, and

vice versa.

It will be readily understood that the actuator can also be used in the same manner to operate any movable device, and in all cases the same delicate and accurate-control of the actuated part is secured by the operation of the manually operated actuating part of the power actuator that is secured by ordinary manual operation, while the power necessary to actually operate 'the actuated part is supplied'by the power actuator. It will also be understood that in all these installations, should the power fail for any reason, the manually operated device can instantly assume direct control of the actuated partl as th movement of the hand lever or other manua'lly actuated part in either direction will, as soon as the lost motion provided between the actuating and actuated parts is taken up, effect themovement of the actuated part in the direction in which the manually operated device is moved. It is unnecessary to employ any retracting spring to insure this result. In operating brake mechanism or any other actuated part which may be provided with a retracting spring, the said spring will of course assist in effecting the rearward movement of the piston, but is not essential to the operation of the mechanism except in case failure of pressure.`

It should also be stated that where the power actuator is employed to operate a device like the rudder of a boat in both directions, where the normal position of the piston will be central between 'the ends of the cylinder, the additional sealing means consisting of the collar, 18, on the v alve sleeve, 16, and the auxiliary valve seat, 18a will be omitted, and the inlet apertures, 16a, will be at all times in communication with the inlet port, 19, and inlet passage, 20. Additional sealing means provided by the valve collar, 18, is very convenient, however, in devices which lock the brakes of a vehicle, are onlyused intermittently as it assists in preventing leakage. v

-Our power actuator may also be convenientlyfemployed forfthe operation of devices at a considerable distance, and even in another vehicle from that inwhich the engine or propelling means is located, as for example, in the case where an automotivevehicle is coupled in the usual or well known way with a trailer or separated vehicle, not provided with automotive means, as is becoming more and more common in the use of auto- 'mobiles In such cases it `is extremely difiiautomobile provided with the usual intake manifold, 206. The automobile is shown as provided with our power actuator, indicated' at 207, the `actuated p art, 208,:of which is connected by a link, 209, with a brake lever, 210, provided with a retracting spring, 211, while the piston rod, 212, is connected by a link, 213, with brake rods for applying the brakes, 203, in substantially the same man'- ner as shown in Fig. 1. 214 is a vacuum tank connected to the passage, 20, of the power actuator by pipe, 215,' and connected to the intake manifold, by pipe, 216, provided with the adjustable restricting valve, 217, and check valve. 218, similar to check valve 23?) of Fig. 1. The trailer, 201, is also shown provided with one of our power actuators, indicated at 219, the actuatedpart, 220, of which i5 connected 'with the brake lever, 210, of the automobile, so that it will be actuated simultaneously with the movement of the actuated part of the power operator, 207. This may beaccomplished inv any desired manner, as for example by a connecting link, 221, extending from the brake lever, 210, to the rear of the automobile, and there being connected by detachable pin, 222, with a flexible wire or rod, 223, extending through a`fiexible metallic tube, .224, the forward end of which is clamped to some part of the frame of the automobile, by means of a detachable clamp, indicated at 225, the flexible rod, 223, being connected at its rear end to the actuating part, 220, of the power actuator carried by the trailer. This construction, illustrated in detail in Fig. 12, permits the removal of the fiexible tube, 224, and flexible rod, 223, from the automobile' when it is desired to separa-te the trailer from the automobile. The piston rod of the power actuator carried by the trailer and indicated at 226, is connected to the brake mechanism for actuating the brakes, 204, on the trailer in any desired manner, or as indicated in Fig. 1.. 227 represents the vacuum tank for the power actuator of the trailer connected to the vacuum port, 20, of the power actuator, by pipe, 228, and connected also to the intake manifold of the engine. This may be accomplished by employing a pipe line, indicated at 229, 230 and 231, of which the section 230 may be a fiexible rubber hose, the section, 229, being provided, as indicated in Fig. 11, with a cut off valve,

232, and a detachable coupling 233, so that l the flexible lpipe connection, 230,. may be detached from the automobile when the trailer 1s not used and the valve, 232, will then be closed to prevent air passing to the manifold. With an installation of-this kindfit will be seen that the flexible hose, 230, and the' flexible rod,' 223, and its protective covering, 2 24, will accommodatev the movements of the trailer independent of the automobile, while maintaining the proper connection between the connected parts. When the foot lever, 210, is depressed, there will be a simultaneous operation of the power actuators, 20.7 and 219, thereby applying the brakes simultaneously to the wheels of both vehicles to the desired extent and preventing the trailer from throwing its load on a hill against the automobile in advance of it. When the foot lever is released,-the brakes of both Vvehicleswill be simultaneously released as the power actuators will operate in the manner herein-V before described.

Where the power actuator isemployed in connection with the steering mechanism 'of a boat, it is to be noted` thatthe provision for lost motion between the manually actuated part` and the actuated p art of the power actuator will not only be an unobjectionable feature, but will,.as a matter of fact, act to relieve the manuallyA operated controlnmecha@ nism, of shocks, which must otherwise be absorbed by the mechanism or by the hands ofthe operator, so that `in such installations the power actuator not only acts to relieve the hands of the operator from the effortand consequent fatigue of operating the steering mechanism, but also acts as a cushioning device or automatic stabilizer for the steering mechanism itself, and .to further relieve the operator from .shocks or sudden movement imparted to the rudder, which would otherwise be transmitted to his hands.

In some instances if found desirable we may equip an automobile with a connection from the. engine cylinder to thehigh pressure end of the actuator cylinder in the same manner as shown in 9.v Thus in Fig. l0 wehave shown a pressure tank 297'connected with a cylinder of the engine bya pipe .298, in which is located an 'adjustable regulating' valve 297 and a check valve 299, the tank 297 being connected by a iiexible pipe 300 withthe pressure side of the actuator in the same'manner asvillustrated in Fig. 9.v

It'is to be noted in connectiomwith our invention that the storage space, or vacuum tank, does n ot serve the ordinary .purpose for which storage tanks are usually employed, namely, to permit an intermittently operated power actuator toV be operated by a pump or other source vof power of insuflicient capacity to operate lthe poweractuator' continuously. The internal combustion motor of an automotive vehicle has many times the capacity needed to operate our suction Asmall quantities of hydrocarbon fuel, which might be so diluted `by' intermittent admissions of relatively large quantities of air exhausted from the actuator that the motor Vwould stall while idling. In our construction, the storage spacel or tank acts as an equalizer or regulator in connection with the restricting means. thus providing means for instantly withdrawing large quantities ofl air from the actuator lcylinder to insure the prompt and immediate action of the piston,

such air being graduallieand more slowly delivered into lthe inta manifold under the action of the restricting valve, so as to prevent interference with-the normal operation of the engine, and-to positively prevent `it from stalling. Our check valve also serves the important purpose of preventing explosive mixture from beingdrawnl into the lsuction pipe, storage space -and actuator cylinder, and valve mechanism, where its presence would do greatl harm, and might result in a serious explosion. When the throttle is closed, rafrification would be produced in the suction pipe and storage space equalto that in the manifold. yOn the opening of thel throttlepthe degree vof rarifica.- tion in the manifold would gradually decrease, and in the absence of our check valve, the,explosive mixturewould be withdrawn from the manifold and carried back into the storage space, and if the valve mechanism happened to be in open position', it might even be'withclrawn into the valve mechanism and the Acylinder of the actuator. Incase of a back fire in the manifold a serious Iexplosion might result, whichfwould demolish the .servo motor, and perhaps seriously injurethe vehicle and its occupants, and in any event, .the presence of explosive mixture would e'ect, aldeposit of gasoline which might reach the valve mechanism, the ysealing means of which is preferably rubber, and this would quickly destroy such sealing means.

lt' is also to be noted that the employment of an actuator having a double acting piston in a. single cylinder, closed at each end, in combination with automobile brake mechanism, as herein shown and described, produces extremely advantageous results. 'The brakes are not only applied bypower, but are positively 'released by power, and the necessity forheavy retracting springs such as are ordinarily used in lautomobile brake' mechanism, is rendered unnecessary. This is particularly important in connectionwith the inf busses o r trucks, in which the strength of the operator may be insuiicient, or Vbarelysufileo Vstallati'on of-our servo-motor system in large cient, to apply the brakes. In such case the full force of the actuator can be applied to the brake mechanism, and a smaller actuator can be used than would be required if a heavy retracting spring must be overcome. In the event of the failure of the source of power, necessitating that the operator must exerta his own strength to apply the brakes, as hereinbefore described, it will be seen that the use of the double acting piston is particularly important, as the operator does not have to use a considerable portion of his strength in overcoming a strong retracting spring, or springs, but can apply practically his entire strength to the brakes for the purpose of stopping the vehicle. l

What we claim and desire to secure by Letters Patent is l. A power actuator comprising among its members a power cylinder closed at both ends, a double acting piston in said cylinder, provided with a hollow piston rod extending through one end of the cylinder, and provided with an inlet aperture, a longitudinally movable reversing valve sleeve extending through the piston and into the hollow piston rod, and provided with separated ports, cerc said valve sleeve and cylinder being provided with auxiliary ports adjacent to the outletpassage, and 'auxiliary valve mechanism located at a distance from the reversing ports and controlling valves therefor for normally closing said ports when the valve sleeve is in normal position, to prevent leakage when the actuator is notin use, an actuated part connected with said piston rod,'and a normally operated actuating part connected to said valve sleeve.

2. A power actuator comprising among its members, a power cylinder closed at both ends, a double acting piston in said cylinder provided with a hollow piston rodextending through one end of the cylinder and provided with an inlet aperture, a longitudinally movable reversing valve sleeve extending through the piston and into the hollow piston rod, said piston being provided with two separated valve chambers communicating by separatedpassages with thecylinder'on oposite faces of the piston respectively, a colar valve mounted on the said sleeve in each of said valve chambers and fitting the walls of said chambers, said sleeve being provided with ports communicating with one'of said chambers and being in communication with said inlet assage, said sleeve having-ports separatedv rom the said first mentioned ports by an impervious partition, and communicating with the other chamber in thel piston, the

cylinder being provided with an outlet pas- L sage on the opposite side of the piston fromA the inlet passage, said sleeve being lprovided with auxiliary ports adapted to be placed in communication with the outlet passage by the forward movement of the sleeve with respect to the piston, and auxiliary valve mechanism normally closing said auxiliary ports,

yan actuated part connected with the piston, and a manually operated actuating part connected with the valve sleeve.

3. A power actuator comprising among its members, a power cylinder closed at both ends, a double acting piston in said cylinder provided with a hollow piston rod extending through one end of the cylinder and provided with'an inlet aperture, a longitudinally movable reversing valve sleeve' extending through the .piston and int the hollow pist0n rod, said pistori being piovided with two separated valve chambers communicating by separated passages with thecylinder on opposite faces of the piston respectively, a collar valve mounted on the said sleeve in each of said valve chambers and fitting the walls of said chambers, said sleeve being provided with ports communicating with one of said chambers and being in communication with said inlet passages, said sleeve being provided with ports communicating with onelof said chambers and being in communication with said inlet passage, said sleeve having portsv separated from thesaid irstm'entioned ports by an'imp'ervious partition, and communicat` ing with the other chamber inthe piston, the cylinderbeing provided with an outlet passage on the opposite side of the 'piston from the inlet passage, said sleeve being provided with lauxiliary ports adapted to be placed iny communication with the. outlet passage by the forward movement of the sleeve with respect to the piston,

and auxiliary valve seats in said piston chambers ada ted to be engaged by the said collar va ves fwhen the sleeve is moved forwardly with respect to the piston, an actuated part connected with the piston rod, and a manually operated part connected with said sleeve. l

4. A power actuator comprising among its members, a power cylinder closedat b oth ends, a double acting piston in said cylinder,

ing through one end of thecylinde'r and being provi ed with an inlet passage, a -longitu inally movable valve sleeve vextending through the piston and into said hollow piston rod and fitting tightly within the same,

the piston being providedfwith separated llll lll

chambers surrounding separated portions of said sleeve and communicating with the in'- terior of the cylinder on opposite sides of the piston respectively, a collar valve on said sleeve in each of saidchambers for controlling said passages, said sleeve being provided with ports communicating with the inlet passage'and normally communicating with one of said chambers in the piston, and adapt-' ed to be brought into communication with the other. of said chambers by the forward movement .of the sleeve*` said sleeve having another series of ports normally in communication with the otherv piston chamber, separated from said first 'mentioned ports by an impervious partit/ion and adapted to y be brought into communication with the cylinder on the forward side of the piston by the longitudinal movement of the sleeve, and to be closed b the following movement of the piston, sai cylinder having an outlet-'pas- Qsage at the end opposite the piston rod, and

said sleeve being provided with Anormally closed auxiliary ports adapted to be placed` in communication with said outlet passagev by the forward movement of the sleeve, means for limiting the relative movement of the sleeve with respect to the piston in both directions, an actuated part connected with the piston rod, and a manually operated actuating part connected with said sleeve.

5. A power actuator comprising among its members, a power cylinder closed at both Iends,.`a double acting piston in said cylinder,

ro'vided with a hollow piston" rod extending through one end of the cylinder and being provided with an Vinlet passage, a longitudinally p movable valve sleeve vextending through the piston and into said hollow piston rod and fitting tightlyy within the same., the piston being provided with separated chambers' surrounding separated portions of said' sleeve and communicating with .the interior of the cylinder, on opposite sides ot` the piston respectively, a collar valve onsaid sleeve in each of said chambers for control- 'ling said passages, said sleeve 'being prothe longitudinal-movement of the sleeve, 'and to be closed by the following movement of the piston, saidcylinder having an outlet passage at the end opposite the piston rod, and a port communicating with said outlet 35 passage, and anannular part in rear of ,said

port fitting said sleeve, said sleeve being pro- Y vided with auxiliary outlet ports adapted to be closed by said annular port, and with an annular auxiliary valve for closing said outlet port when the sleeve isvin its normal position, an actuated part connected with the piston rod, and a manually operated-actuating part connected with said sleeve.

6. A power actuator comprising among its members a power cylinder closed at both ends,

a double ,acting piston in said cylinder provided with a hollow piston rod extending,

through one end of Athe cylinder, and provided with an inlet aperture, a longitudinallyv movable reversing sleeve extending throng the opposite end of the cylinder, through the piston and into the hollow piston rod, and.

provided with separated ports, certain of said ports being connected with said inlet aperture, and others of said ports being adapted to be connected to an outlet passage from the cylinder, said piston being provided with separated cylindrical chambers connected by lateral ports and passages, tlie one with the cylinder on one side of the piston, and the other with the cylinder on the other side of the piston, each of said chambers being provided with a transversely disposed annular valve seat, a collar valve on` said valve sleeve within each of said chambers, each having a lateral surface for opening and .closing the piston port, and a transversely disposed annular portion toengage the transverse annular valve seat in said chamber to prevent leakage, a manually operated device connected to the valve sleeve, and an actuated device connected with the piston rod.

7. In a servo-motor system, the combination with an internal combustion engine, provided with'a suction passage for explosive charges, of a power actuator comprising a `cylinder,"a piston movable therein, and re- 'versing valve mechanism, a suction pipe or passage connecting the reversing valve mephanism of the actuator with the suction passage of the engine, and restricting means in said suction pipe or passage between the actuator and. thesuction passage of theengine for preventing any air withdrawn from the actuator from being delivered into the suction passage ofthe engine in such large quantities at a time as to materially interferewith the normal operationv of the engine under the control of the throttle valve or to stall the engine if idling, means for connecting the reversing valve mechanism of the actuator to the explosive chamber, of a cylinder of the engine for enabling pressure higher than atmosphere to be applied to one .side of the actuator piston simultaneously with the connectionof the said suction pipe with the actusol ator cylinder on the other side lofl the piston, v

to insurethe effective operation'of the actuator pistonby either suction or pressure from Y engine, or bo h;

8. Brake mechanism comprising, in combination, an air brake, mechanical connections for operating the brake independently of the air pressure, and an air valve controlling the air brake and forming a tension element in said connections and arranged to operate the air brake when tension is applied to said con nectyio'ns.

In testimony whereof We aHiX our signatures.

CALEB S. BRAGG. VICTOR W. KLIESRATH.

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